Method of making reinforced molded conduits



' T. E. MURRAY.

METHOD OF MAKING REINFORCED MOLDED CONDUITS.

APPLICATION FILED IAN. 6, 1921.

1,387,065. Patented Aug. 9, 1921'.

rrEo STATES THOMAS E. MURRAY, F BROOKLYN,-NEW YORK.

METHQD ,OF MAKING- REDIFORGED .MOLDED CONDUI'IS.

To all whom it may concern:

Be-it known that I, THOMAS E. MURRAY, a

citizen of the United States; residing at Brooklyn, in the county of Kings and State of New York, have invented a certain new and useful Improvement in Methods of Making Reinforced Molded Conduits, of which the following is a specification.

Conduits of cement or like plastic material have been molded upon a spiral core of wire or the like provided with a cover or wrap.-

ing of paper or similar flexible material.

y present invention is a method of making a reinforced conduit of this type.

In' the accompanying drawing- Figure 1 represents in longitudinal section a portion of theconduit and core therein. Fig. 2 is a transverse section on the line 2, 2 of Fig. 1. Fig. '3 is a similar transverse section, with the spiral core removed.

Similar numbers of reference indicate like parts.

In performing'my method, I first make a spiral core 1 of wire or strip metal. Upon said core I apply preferably by wrapping, a cover -2 of paper or similar flexible sheet material. To this cover I next apply a coating 3 of pitch or other viscid adhesive material which will harden. While the pitch coating I is still viscid, I wind thereon a sp-lralwlre or metal strip 4, and upon the 'SBJd coated and woundoore I apply plastic cement or concrete 5 to form the conduit body, which I allow to become hard. Finally, I withdraw V 1 the core 1.

Specification of Letters Patent. Application flied .Tanuary 6, 1921.

- said lining with Patented Aug. 2, 1921. Serial No. 435,406.

The spiral wire 4 becomes embedded in the wall of same. The cover 2 remains firmly attached to the spiral 4 and cement 5 by the pitch 3, and so forms a smooth inner surface for the conduit bore.

I claim:

1. The method of making a reinforced molded conduit, which consists in, first, ap-

plying to a tubular lining constructed to fit within said conduit, a coating ofadhesive material; second, inclosing said ing in a spiral of metal; third, coating plasticmatenal to form the conduit body. i

2. The method of making a reinforced molded conduit, which consists in, first, producing a spiral metal core second, covering said core with flexible material; third, applying to said cover a coating of adhesive 'material; fourth, inclosing said coated core in a spiral strip of metal; upon said coated and covered core a conduit body of plastic material and allowing same to harden, and sixth, withdrawing said spiral core. 1

In testimony whereof I have afiixedmy signature in presence of two witnesses.-

THOMAS E. MURRAY.

fifth, forming I Witnesses: GERTRUDE T. PORTER, MAY T. MCGABRY.

the conduit, and so reinforces the coated lin- 

